An organic light emitting diode (OLED) typically includes an anode, an organic layer including a light emitting layer, and a cathode. Optionally, the organic light emitting diode may further includes one or a combination of a hole transport layer, a hole injection layer, an electron transport layer, and an electron injection layer. In an organic light emitting diode, an electric field is applied between the anode and the cathode to inject electrons from the cathode into the light emitting layer and holes from the anode into the light-emitting layer. The electrons and the holes then recombine together in the light emitting layer to generate excitons. When the excitons return to the ground state, their energy is released in the form of light.